Not in my day-to-day work. The deterioration is very clear.

Most people want the lowest common denominator information. They want to know what most other people think and want.

HN and their desire for niche information is just not representative of the average human.

Technically, revenue decline would be a lagging indicator of poor search results and poor user experience.

But agreed.

Product quality is a leading indicator of profit. If the HN perception is accurate, then it will be a problem in the long term.

This is very noticeable. I remember everyone here saying Atlassian was a sinking ship when they switched to cloud-only. Ever since, its stock has almost doubled. I can probably think of a pretty big list of other things where HN hivemind completely misaligns with how 90% of the normal population thinks.

Doesn't really follow. a) Google is a lot more than search and b) it's not like people noticing "crap, search results are getting worse" suddenly stop using it entirely, given there is no clearly superior competitor. Similarly with many other products.